A conventional commonly used ultrasound apparatus was composed of: an ultrasound transmission/reception controlling means for controlling the ultrasound transmission/reception; an ultrasound transmission/reception means for transmitting and receiving the ultrasonic waves to/from the object; a tomographic scanning means for obtaining a tomographic image data repeatedly with predetermined cycles in the body of the object including the dynamic tissues from the ultrasound transmission/reception controlling means; and an image display means for displaying the time-series tomographic image data being obtained by the tomographic scanning means.
And the configuration of organism tissues of the object was displayed as, for example, B-mode tomographic image.
Recently, two methods for imaging have been suggested. One method is to apply an external force artificially from the body surface of the object with a pressure device or a probe and compress the internal organism tissues, obtain the displacement in the respective points using the calculation of correlation coefficient of the ultrasound reception signals of adjacent two frames in time series (the two frames that follows in the series), measure the distortion by spatially differentiating the displacement, and construct the images of the distortion data. Another method is to construct the images of the elastic modulus such as Young's modulus of organism tissues from the stress distribution and the distortion data by external force. By the elastic images based on the distortion and/or elastic modulus data (hereinafter referred as elastic frame data), it is possible to measure the hardness or softness of organism tissues and display it as elastic images.
These methods for the ultrasonic diagnostic apparatus are disclosed in Patent Document 1 and Patent Document 2.
Patent Document 1: JP-A-1993-317313
Patent Document 2: JP-A-2000-060853
However, these methods for constructing images of elastic modulus data of organism tissues by conventional ultrasound apparatuses merely recognize the degree of hardness with regard to an actual disease, which does not give an index for diagnosing the disease.